The present invention relates to a capsule, device, and method for preparing infused beverages.
In particular, the present invention relates to a capsule containing dry infusible matter for preparing infused beverages, and comprising a front face, comprising a filter wall and a rim; a back face substantially opposed to said front face along a main longitudinal axis of the capsule, and comprising a frangible region for the injection of infusion liquid; and a solid envelope between said front face and said back face.
In the present specification, the term “capsule” is preferentially used, although it should be considered synonymous with the terms “cartridge”, “package” or “container” used elsewhere in this particular technical domain.
The present invention also relates to a device for preparing infused beverages comprising the abovementioned capsule; an infusion vessel; and injecting means for introducing an infusing liquid into said capsule.
In the present specification, the term “infusing liquid” generally refers to the liquid used to infuse ingredients contained in the dry infusible matter, so as to produce an infused beverage wherein said infusing liquid carries said ingredients in dissolved or suspended form. Usually, but not necessarily, the infusing liquid will be hot water, and the infused beverage a tea, such as black tea, green tea, white tea, flavoured tea, or also a so-called herbal or fruit tea using infusible matter other than the leaves of the tea plant (for instance, rooibos, camomile, peppermint, etc.).
Similar capsules and devices are known from the state of the art.
Canadian patent application CA 2 448 474 A1 discloses one such capsule. However, this capsule presents several drawbacks. The capsule disclosed in this document is particularly adapted to use for preparing beverages by percolation, in which a hot liquid percolates down continuously through the matter contained in the capsule. For this, the capsule is placed in a horizontal position, with the back face comprising the liquid injection point at the top, and the front face at the bottom. This method, though appropriate for preparing such beverages as coffee, is entirely inappropriate for, for instance, tea, which requires a longer and gentler infusion. With the infusing liquid flowing too rapidly downwards under the influence of gravity, it provokes a chaotic and exceedingly fast breakdown of various tea molecules, ruining the quality and flavour of the infusion.
In order to solve this problem, it has been proposed to place such capsules against a side opening of an infusion vessel. However, such a position has the drawback of being considerably more leak-prone than one in which the front face remains in a substantially horizontal position.
This problem has been addressed in a number of similar capsules for preparing coffee by incorporating a sealing ring in the rim around the front face, as disclosed, for instance, in WO 2007/137974, WO 2007/122208, or EP 0 468 079. However, these prior art capsules are adapted to the preparation of espresso coffee by injecting water at high pressure into the capsule and extracting it at the front face, as illustrated in FIG. 1. Since the water injection point 1 and the back face 2 of the capsule 3 are not sealed, the high-pressure water 4 both percolates through the ground coffee in the capsule 3 and flows around the envelope 5 of the capsule 3. In use, the water pressure thus pushes the capsule 3 forward, pressing the front of the rim 6 against an opposite surface 7 of the receptacle receiving the capsule 3. The principal purpose of the sealing rings in these prior art capsules is to prevent leaks of high-pressure water 4 from behind the rim 6.
In prior art document EP 1 929 904 A, one of the embodiments of the capsule presents a backwards taper of the rim. This rim, however, is resiliently deflectable, for preventing leaks of high-pressure water from behind the rim.